class_docstr: Represents a resource requirement in an execution environment for an operator.
  
  :param name: Name of the resource
  :param units_str: The string representing the units of a resource (e.g. MB for a CPU
      resource) to be used for display purposes
  :param qty: The number of units of the specified resource that are required for
      execution of the operator.
docstr: The string representing the units of a resource.
docstr_tok: ["The","string","representing","the","units","of","a","resource","."]
code: def units_str(self):
      """The string representing the units of a resource."""
      return self._units_str
  
imports: from __future__ import annotations
  from airflow.configuration import conf
  from airflow.exceptions import AirflowException
label_desc: Use image node_id 5 for calling the Resource obj's underlying member method code with example usage: obj.units_str() and returns: self